Plants perennial. Culms densely tufted, up to 50 cm, trigonous, tenuous, glabrous. Leaves shorter than culms, flat or margins involute, 1-2 mm wide, basal persistent leaf sheaths dark brown. Involucral bracts leafy, shorter than inflorescence, long sheathed. Spikes 5 or 6, bisexual, androgynous, single, distant, linear-cylindric, 30-40 × 3-4 mm, terminal one with 1(or 2) branches, male part much longer than female part, branched spikes arising from cladoprophylls with a developed female flower inside; male part of lateral spikes much shorter and with only few flowers, female part with dense numerous flowers; peduncles of spikes tenuous, lowest one up to 20 cm, upper ones shorter; male glumes purplish brown, oblong-lanceolate, 4-4.5 mm, membranous, apex acuminate; female glumes purplish brown laterally, green at middle, oblong, 3.5-4 mm, papery, 3-veined, scabrid on veins, margins narrowly hyaline, apex rounded, apiculate. Utricles yellowish green, obovate-lanceolate, compressed trigonous, 3.5-4 mm, papery, pubescent, with 2 raised lateral veins and no fine veins abaxially, base attenuate into a short stipe, apex contracted into a short excurved beak, orifice truncate. Nutlet obovate-oblong, 2.2-2.5 mm, sessile, apex not apiculate; style base slightly thickened; stigmas 3. Rachilla ca. 0.3 mm, flat.